I bought the tickets during the Black Friday on the Expedia website so I paid half the price, about 25 euro, but the tickets are very expensive, 45/ 50 usd.
I think that the right price is mine because we were 3 and with the total of full price we could have done the same thing with Uber.
We took it at Union Square, we immediately went upstairs, you can use the audio guide in your own languages, it’s useful to know the places with more explanations.
We decided to get off the bus in Lombard street, Golden gate, we followed the rest of the tour from the bus.
You can get off and on as you wish, all the tour lasts 2 hours.